Using mixture modeling to examine differences in perceptual decision-making as a function of the time and method of participant recruitment

We examine whether perceptual decision-making differs as a function of the time in the academic term and whether the participant is an undergraduate participating for course credit, a paid in-person participant, or a paid online participant recruited via Amazon Mechanical Turk. We use a mixture modeling approach within an evidence accumulation framework that separates stimulus-driven responses from contaminant responses, allowing us to distinguish between performance when a participant is engaged in the task and the consistency in this task focus. We first report a survey showing cognitive psychologists expect performance and response caution to be lower among undergraduate participants recruited at the end of the academic term compared to those recruited near the start, and highest among paid in-person participants. The findings from two experiments using common paradigms revealed very little evidence of time-of-semester effects among course credit participants on accuracy, response time, efficiency of information processing (when engaged in the task), caution, and non-decision time, or consistency in task focus. However, paid in-person participants did tend to be more accurate than the other two groups. Groups showed similar effects of speed/accuracy emphasis on response caution and of discrimination difficulty on information processing efficiency, but the effect of speed/accuracy emphasis on information processing efficiency was less consistent among groups. We conclude that online crowdsourcing platforms can provide quality perceptual decision-making data, but recommend that mixture modeling be used to adequately account for data generated by processes other than the psychological phenomena under investigation.

Evaluating CloudResearch's Approved Group as a solution for problematic data quality on MTurk

Maintaining data quality on Amazon Mechanical Turk (MTurk) has always been a concern for researchers. These concerns have grown recently due to the bot crisis of 2018 and observations that past safeguards of data quality (e.g., approval ratings of 95%) no longer work. To address data quality concerns, CloudResearch, a third-party website that interfaces with MTurk, has assessed ~165,000 MTurkers and categorized them into those that provide high- (~100,000, Approved) and low- (~65,000, Blocked) quality data. Here, we examined the predictive validity of CloudResearch's vetting. In a pre-registered study, participants (N = 900) from the Approved and Blocked groups, along with a Standard MTurk sample (95% HIT acceptance ratio, 100+ completed HITs), completed an array of data-quality measures. Across several indices, Approved participants (i) identified the content of images more accurately, (ii) answered more reading comprehension questions correctly, (iii) responded to reversed coded items more consistently, (iv) passed a greater number of attention checks, (v) self-reported less cheating and actually left the survey window less often on easily Googleable questions, (vi) replicated classic psychology experimental effects more reliably, and (vii) answered AI-stumping questions more accurately than Blocked participants, who performed at chance on multiple outcomes. Data quality of the Standard sample was generally in between the Approved and Blocked groups. We discuss how MTurk's Approval Rating system is no longer an effective data-quality control, and we discuss the advantages afforded by using the Approved group for scientific studies on MTurk.

Participant recruitment among vulnerable populations: An experience from a qualitative study among refugee adolescents in Germany

When it comes to actual practice, comparing to theoretical plans, the study progress is much more complicated due to both predicted and unpredicted challenges in the study participant recruitment. The situation is even more difficult if the research team deal with a vulnerable population. The current article represents and discusses the recruitment process for a currently unpublished qualitative study, conducted in Germany in 2021, as the first phase of our project: SC-SD4ASA: A self-care/self-development guidebook for asylum-seeking adolescents. First a brief of the study methodology is outlined and then, the strategies used to reach the potential participants including major/government organizations for refugees, private organizations and local centers, social media, youth's favorite public places, and participatory strategy are discussed. Finally, our experience of participant recruitment challenges in this study is reviewed. We hope that the points raised from our experience can be helpful to other researchers in the same field. Overall, the experience of recruiting our participants emphasized the necessity for a dedicated point of contact for consultation and the provision of resources to connect with potential participants for researchers in the field of refugee and migrant health. Furthermore, the influence of trustworthy individuals, particularly within the community, should not be underestimated. Their assistance can significantly benefit the advancement of a research project.

Preparing for future European efficacy trials of interventions to prevent HIV and other sexually transmitted infections: Lessons on willingness to participate and barriers to participation from ten German clinics serving behaviorally vulnerable men who have sex with men

Future efficacy testing of interventions to prevent HIV or other infections will require engagement of vulnerable populations. We characterized willingness to participate in a future HIV vaccine trial and barriers to participation among men who have sex with men in a 12-month German cohort study. Among 1015 participants at enrollment, 604 (60%) reported willingness, 60 (6%) were unwilling, 351 (35%) were unsure or refused to answer. Among those unwilling, the primary reason was fear of getting HIV. Among those willing, reasons included protection against HIV and furthering scientific knowledge. In a multivariable logistic regression model, higher odds of willingness to participate were seen among participants at the 12-month visit (aOR: 1.09, 95% CI: 1.04-1.15) and with prior knowledge of HIV vaccine research (aOR: 1.14, 95% CI: 1.06-1.23). Educating potential participants about vaccine research may facilitate recruitment and participation in future trials of HIV vaccine candidates and other prevention interventions.

Presenting Methodological Resilience for Conducting Research with Vulnerable Populations During Current and Future Pandemics: A Case Study with IPV Shelters and Survivors in the United States

Purpose

In this brief report, we highlight the challenges that we experienced while attempting to conduct primary data collection with intimate partner violence (IPV) survivors living in an IPV emergency shelter throughout the prolonged COVID-19 pandemic and our strategies to overcome them.

Method

In the summer of 2021, we began collecting data on a study investigating maternal-child bonding while living in IPV emergency shelters. We proposed a 14-day electronic daily diary methodology with follow-up semi-structured interview. The purpose of the study was to understand what factors affect maternal-child bonding to support survivors' relationships with their children while living in an emergency shelter.

Results

We encountered two global obstacles to study implementation: the Institutional Review Board (IRB) pausing in-person data collection and low IPV shelter utilization. In what we term methodological resilience, we engaged in innovative and flexible team work to overcome these barriers. Specific strategies centered on creating an entirely remote data collection process and expanding our geographic area and participant eligibility criteria.

Conclusions

Implications for researchers include greater communication with IRB offices, planning for multi-state recruitment, triangulated recruitment methods, reminder texts for participants and incremental incentives to ensure continued engagement with the study.

Educating students while recruiting underrepresented populations for Alzheimer's disease research: the Student Ambassador Program

BACKGROUND

Increasing numbers of patients with Alzheimer's Disease and related disorders (ADRD) necessitates increasing numbers of clinicians to care for them. Educational programming related to community outreach with older adults may help inspire interest in future ADRD clinical careers, while increasing awareness of ADRD in the community and aiding recruitment of underrepresented participants into research studies.

METHOD

The Boston University Alzheimer's Disease Research Center (BU ADRC) created the BU ADRC Student Ambassador Program, where medical students, graduate students, and undergraduates interested in medicine completed a curriculum during the academic year that included six educational and three outreach events, including monthly dementia-focused didactic meetings and outreach focusing on Black participant recruitment. A pre-post program survey design was implemented to assess changes in students' knowledge of and attitudes toward dementia and related disorders.

RESULTS

Between September 2015 and May 2020, thirty-seven students completed the program. Following program completion, students demonstrated increased knowledge of dementia and willingness to work with patients with dementia, as well as more positive attitudes toward patients and the role of empathy in physician practice. In terms of recruitment benefits, the students helped the BU ADRC reach older adults from underrepresented groups who could serve as participants in future research studies.

CONCLUSIONS

The BU ADRC Student Ambassador Program can serve as a model for other clinical research programs who wish to encourage students to consider a career in a specific field. In addition, this model has the potential to increase enrollment of participants to research studies. We discuss limitations of our initial efforts and directions for future work to quantify the anticipated benefits for student education and participant recruitment.

Recruitment and retention of emerging adults in lifestyle interventions: Findings from the REACH trial

OBJECTIVE

Emerging adulthood (EA) is a critical time to promote cardiometabolic health, but EAs are underrepresented in lifestyle intervention trials. Knowledge gaps exist regarding how best to recruit and retain sociodemographically diverse EAs. Our goal was to begin to address these gaps using data from the Richmond Emerging Adults Choosing Health (REACH) Trial.

METHODS

REACH was a comparative efficacy trial for EAs, age 18-25, with a body mass index of 25-45 kg/m2. Enrollment goals were: N = 381, ≥40% underrepresented race/ethnicity, ≥30% men, ≥85% retention at 6 months. We translated formative work into a recruitment and retention plan, examined yield for recruitment and retention overall, and by gender and race/ethnicity, as well as cost data. Descriptive statistics and chi square tests were used.

RESULTS

Enrollment benchmarks were met overall (N = 382) and for participants from underrepresented race/ethnic backgrounds (58.0%), but not men (17.3%). The most common recruitment sources were email (26.9%), radio (22.2%), and online radio (15.4%); this pattern largely held true across gender and race/ethnic groups, though word of mouth and participant referral together accounted for nearly a quarter of enrolled men. Costs averaged $155 per randomized participant. Retention was 89% at 3-months, 84% at 6-months (primary endpoint) and 80% at 12-months (follow-up), with no significant differences by gender or race/ethnicity (all p's > 0.05). Retention did not differ by recruitment method (p = .69).

CONCLUSIONS

Grounding our approach in formative data and embracing participants as partners in research contributed to the recruitment and retention of sociodemographically diverse EAs. Additional efforts are needed to enroll EA men.

Recruiting hard-to-engage groups to online psychosocial interventions: Experiences from an RCT study targeting adolescents with a visible difference

Online interventions have the potential to reach individuals who are otherwise difficult to engage due to stigma and sensitive topics. However, these individuals also tend to be hard to recruit in clinical trials, a crucial step in order to provide evidence-based interventions. This highlights a need for more information about efficient recruitment strategies for difficult-to-engage groups. The present study aimed to share the systematised experiences of recruiting adolescents with a visible difference to an online psychosocial intervention RCT. With the intention to recruit 160 participants (age 12-17), recruitment efforts were nationwide and included multiple arenas (e.g., hospitals, schools, social media), and methods (e.g., in-consultation, targeted letters, posters). Ultimately, 102 participants were recruited, and results showed that recruitment involving patient organisations, hospital departments, and specialised resource centres were most successful in reaching participants. The most efficient recruitment strategy was targeted letters sent home to eligible patients/members, as 78% of the participants were recruited this way. Media and social media recruitment efforts yielded comparatively few participants. No participants were recruited through schools and educational health care services, primary health care services, or municipal and regional authorities. Our results are discussed in relation to barriers with recruiting difficult-to-engage groups to RCTs, providing useful recruitment tools to future similar studies. For instance, future studies are recommended to utilise targeted approaches over general population approaches. Also, results from recruitment efforts should routinely be reported, as this ultimately will provide more general strategies for effective recruitment and support studies in reaching recruitment goals.

Effects of financial incentives on volunteering for clinical trials: A randomized vignette experiment

BACKGROUND

Financial incentives may aid recruitment to clinical trials, but evidence regarding risk/burden-driven variability in participant preferences for incentives is limited. We developed and tested a framework to support real-world decisions on recruitment budget.

METHODS

We included two phases: an Anchoring Survey, to ensure we could capture perceived unpleasantness on a range of life events, and a Vignette Experiment, to explore relationships between financial incentives and participants' perceived risk/burden and willingness to participate in high- and low-risk/burden versions of five vignettes drawn from common research activities. We compared vignette ratings to identify similarly rated life events from the Anchoring Survey to contextualize ratings of study risk.

RESULTS

In our Anchoring Survey (n = 643), mean ratings (scale 1 = lowest risk/burden to 5 = highest risk/burden) indicated that the questions made sense to participants, with highest risk assigned to losing house in a fire (4.72), and lowest risk assigned to having blood pressure taken (1.13). In the Vignette Experiment (n = 534), logistic regression indicated that amount of offered financial incentive and perceived risk/burden level were the top two drivers of willingness to participate in four of the five vignettes. Comparison of event ratings in the Anchoring Survey with the Vignette Experiment ratings suggested reasonable concordance on severity of risk/burden.

CONCLUSIONS

We demonstrated feasibility of a framework for assessing participant perceptions of risk for study activities and discerned directionality of relationship between financial incentives and willingness to participate. Future work will explore use of this framework as an evidence-gathering approach for gauging appropriate incentives in real-world study contexts.

Principles for the production and dissemination of recruitment material for three clinical trials of an online intervention

Some health research studies recruit participants through electronic mechanisms such as the placement of messages on social media platforms. This raises questions for ethics committee oversight, since effective social media campaigns might involve the production and dissemination of hundreds of contemporaneous messages. For the Narrative Experiences Online (NEON) study, we have developed nine principles to control the production and dissemination of promotional material. These have been approved by an ethics committee and enable the audit of our recruitment work. We propose that the drafting for approval of recruitment principles by health research studies may, in many cases, strike an appropriate balance between enabling ethical oversight of online recruitment work and the potential burden of message review.

Using digital tools in the recruitment and retention in randomised controlled trials: survey of UK Clinical Trial Units and a qualitative study

BACKGROUND

Recruitment and retention of participants in randomised controlled trials (RCTs) is a key determinant of success but is challenging. Trialists and UK Clinical Research Collaboration (UKCRC) Clinical Trials Units (CTUs) are increasingly exploring the use of digital tools to identify, recruit and retain participants. The aim of this UK National Institute for Health Research (NIHR) study was to identify what digital tools are currently used by CTUs and understand the performance characteristics required to be judged useful.

METHODS

A scoping of searches (and a survey with NIHR funding staff), a survey with all 52 UKCRC CTUs and 16 qualitative interviews were conducted with five stakeholder groups including trialists within CTUs, funders and research participants. A purposive sampling approach was used to conduct the qualitative interviews during March-June 2018. Qualitative data were analysed using a content analysis and inductive approach.

RESULTS

Responses from 24 (46%) CTUs identified that database-screening tools were the most widely used digital tool for recruitment, with the majority being considered effective. The reason (and to whom) these tools were considered effective was in identifying potential participants (for both Site staff and CTU staff) and reaching recruitment target (for CTU staff/CI). Fewer retention tools were used, with short message service (SMS) or email reminders to participants being the most reported. The qualitative interviews revealed five themes across all groups: 'security and transparency'; 'inclusivity and engagement'; 'human interaction'; 'obstacles and risks'; and 'potential benefits'. There was a high level of stakeholder acceptance of the use of digital tools to support trials, despite the lack of evidence to support them over more traditional techniques. Certain differences and similarities between stakeholder groups demonstrated the complexity and challenges of using digital tools for recruiting and retaining research participants.

CONCLUSIONS

Our studies identified a range of digital tools in use in recruitment and retention of RCTs, despite the lack of high-quality evidence to support their use. Understanding the type of digital tools in use to support recruitment and retention will help to inform funders and the wider research community about their value and relevance for future RCTs. Consideration of further focused digital tool reviews and primary research will help to reduce gaps in the evidence base.

Google AdWords and Facebook Ads for Recruitment of Pregnant Women into a Prospective Cohort Study With Long-Term Follow-Up

Objectives Several types of epidemiologic studies suffer from decreasing participation rates, resulting in potential selection bias and delay or termination of studies. We aimed to determine the feasibility of online methods for recruitment of pregnant women into a prospective cohort study. Methods In addition to traditional recruitment through prenatal care providers, we advertized participation in the PRegnancy and Infant DEvelopment (PRIDE) Study, an ongoing prospective cohort study with long-term follow-up in The Netherlands enrolling women in early pregnancy, through Google AdWords (30 days) and Facebook Ads (31 and 27 days) campaigns between September 2016 and January 2017. We calculated costs per eligible participant and compared demographics, health-related characteristics, and follow-up rates between participants recruited through online methods and prenatal care providers. Results During the study period, we recruited six women through AdWords (€54.28 per participant), 59 through Facebook (€10.17 per participant), and 327 through prenatal care providers (no valid cost estimate available). Facebook participants seemed to be younger (29.0 vs. 30.7 years), to have a higher body mass-index and/or low/intermediate education (27.0 vs. 24.0 kg/m² and 41 vs. 25%, respectively), and to start prenatal care in secondary care more often (12 vs. 5%) than participants recruited through prenatal care providers. Item non-response and loss to follow-up rates were higher among women recruited online than among those recruited through prenatal care providers. Conclusion Google AdWords did not contribute substantially, but Facebook Ads may complement traditional recruitment methods of pregnant women into prospective cohort studies, despite challenges that may threaten internal validity.

A systematic review of non-randomised evaluations of strategies to improve participant recruitment to randomised controlled trials

Background: Recruitment to trials can be challenging. Currently, non-randomised evaluations of trial recruitment interventions are rejected due to poor methodological quality, but systematic assessment of this substantial body of work may inform trialists’ decision-making about recruitment methods. Our objective was to quantify the effects of strategies to improve participant recruitment to randomised trials evaluated using non-randomised study designs.

Methods: We searched relevant databases for non-randomised studies that included two or more interventions evaluating recruitment to trials. Two reviewers screened abstracts and full texts for eligible studies, then extracted data on: recruitment intervention, setting, participant characteristics, number of participants in intervention and comparator groups. The ROBINS-I tool was used to assess risk of bias. The primary outcome was the number of recruits to a trial.

Results: We identified 92 studies for inclusion; 90 studies aimed to improve the recruitment of participants, one aimed to improve the recruitment of GP practices, and one aimed to improve recruitment of GPs. Of the 92 included studies, 20 were at high risk of bias due to confounding; the remaining 72 were at high risk of bias due to confounding and at least one other category of the ROBINS-I tool. The 20 studies at least risk of bias were synthesised narratively based on seven broad categories; Face to face recruitment initiatives, postal invitations and responses, language adaptations, randomisation methods, trial awareness strategies aimed at the recruitee, trial awareness strategies aimed at the recruiter, and use of networks and databases. The utility of included studies is substantially limited due to small sample sizes, inadequate reporting, and a lack of coordination around deciding what to evaluate and how.

Conclusions: Careful thought around planning, conduct, and reporting of non-randomised evaluations of recruitment interventions is required to prevent future non-randomised studies contributing to research waste.

Registration: PROSPERO CRD42016037718

Recruitment of men to a multi-centre diabetes prevention trial: an evaluation of traditional and online promotional strategies

Background

Effective interventions are required to prevent the current rapid increase in the prevalence of Type 2 diabetes. Clinical trials of large-scale interventions to prevent Type 2 diabetes are essential but recruitment is challenging and expensive, and there are limited data regarding the most cost-effective and efficient approaches to recruitment. This paper aims to evaluate the cost and effectiveness of a range of promotional strategies used to recruit men to a large Type 2 diabetes prevention trial.

Methods

An observational study was conducted nested within the Testosterone for the Prevention of Type 2 Diabetes (T4DM) study, a large, multi-centre randomised controlled trial (RCT) of testosterone treatment for the prevention of Type 2 diabetes in men aged 50–74 years at high risk of developing diabetes. Study participation was promoted via mainstream media—television, newspaper and radio; direct marketing using mass mail-outs, publicly displayed posters and attendance at local events; digital platforms, including Facebook and Google; and online promotions by community organisations and businesses. For each strategy, the resulting number of participants and the direct cost involved were recorded. The staff effort required for each strategy was estimated based on feedback from staff.

Results

Of 19,022 men screened for the study, 1007 (5%) were enrolled. The most effective recruitment strategies were targeted radio advertising (accounting for 42% of participants), television news coverage (20%) and mass mail-outs (17%). Other strategies, including radio news, publicly displayed posters, attendance at local events, newspaper advertising, online promotions and Google and Facebook advertising, each accounted for no more than 4% of enrolled participants. Recruitment promotions cost an average of AU$594 per randomised participant. The most cost-effective paid strategy was mass mail-outs by a government health agency (AU$745 per participant). Other paid strategies were more expensive: mail-out by general practitioners (GPs) (AU$1104 per participant), radio advertising (AU$1081) and newspaper advertising (AU$1941).

Conclusion

Radio advertising, television news coverage and mass mail-outs by a government health agency were the most effective recruitment strategies. Close monitoring of recruitment outcomes and ongoing enhancement of recruitment activities played a central role in recruitment to this RCT.

Trial registration

ANZCTR, ID: ACTRN12612000287831. Registered on 12 March 2012.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3485-2) contains supplementary material, which is available to authorized users.

Telephone call reminders did not increase screening uptake more than SMS reminders: a recruitment study within a trial

OBJECTIVES

The aim of the study was to compare the response rates and costs of phone call vs. short message service (SMS) screening reminders to prospective randomized controlled trial (RCT) participants.

STUDY DESIGN AND SETTING

This study was a randomized evaluation within a large Australian diabetes prevention RCT. Participants were men aged 50-74 years, overweight or obese, without a previous type 2 diabetes diagnosis. Those eligible on a prescreening questionnaire who did not attend a further screening assessment within 4 weeks were randomized to receive an SMS or phone call reminder (N = 709). The primary outcome was attendance for further screening assessment within 8 weeks of prescreening.

RESULTS

Attendance was 18% (62/354) in the SMS reminder group, and 23% (80/355) in the phone reminder group, with no statistically significant difference in response according to reminder type (relative risk = 1.29, 95% confidence interval [CI]: 0.96-1.73, P = 0.09). The lower confidence limits for response to SMS (95% CI: 14-22%) and phone reminders (95% CI: 18-27%) did not include the 8-week attendance rate before this evaluation, 12%. Phone reminders cost substantially more than SMS reminders (AU$6.21 vs. AU$0.53 per reminder).

CONCLUSION

SMS reminders were as adequate a method as phone reminders to boost RCT screening uptake and were considerably more affordable.

Adapting clinical trial design to maintain meaningful outcomes during a multicenter asthma trial in the precision medicine era

Precision medicine is expected to impact the care of people with asthma, given its high disease prevalence, heterogeneity of pathophysiologic mechanisms, and consequent clinical phenotypes. A novel phenotype-stratified clinical trial conducted by the NHLBI AsthmaNet Consortium, titled Steroids in Eosinophil Negative Asthma (SIENA), was a randomized, multicenter, clinical trial that prospectively stratified individuals according to their baseline level of sputum inflammation during a screening period. Two phenotypic strata were assigned based on an a priori defined extent of sputum eosinophilia (Eos Low versus Eos High). This article describes: the scientific premise for the trial design, including assumptions used for power calculations; modifications to the analysis plan implemented after the trial started due to a higher than expected prevalence of one phenotypic stratum which impacted the ability to accrue sufficient subjects within the planned budget and study period; investigator alternatives to address the strata imbalance weighing scientific impact and study feasibility; and the final modified SIENA study design and analysis plan. SIENA was successfully completed in a manner that maintained meaningful outcomes. We conclude with recommendations for incorporation of pre-specified contingency plans into phenotype-directed protocols, to address the potential for differences in observed compared to estimated prevalence of different phenotypes in a study population. These approaches can be applied to precision medicine trials for the future.

Impact of informed consent content and length on recruitment of older adults into a community based primary prevention trial

Aims

To compare recruitment, refusal and randomisation rates of older adults into a general practice-based clinical trial with two versions (varied format, content and language) of the Participant Information and Consent Form (PICF).

Methods

This prospective PICF study was conducted within the STAREE (STAtins in Reducing Events in the Elderly) clinical trial. Participants phone screened between October 2015 to February 2016 formed Group 1 and were mailed the extended PICF version and participants phone screened between October 2016 to February 2017 formed Group 2 and were mailed the shortened PICF version. Participants who attended a subsequent baseline screening visit were guided through a comprehensive informed consent process.

Results

During the screening phase of the trial, the likelihood of refusing trial participation was lower in Group 2 compared to Group 1 equating to an overall 23% reduction in risk (RR 0.77, P = 0.005, 95% CI 0.62–0.95). Group 2 had a 6.4% higher randomisation rate compared with Group 1 (65.3% versus 58.9% respectively) but this difference was not statistically significant. Factors associated with trial participation were male gender, age between 70 and 75 years and living alone (all p < .0.05).

Conclusions

Whilst avoiding lengthy and complex PICF documents may assist with initial trial engagement, it needs to be supplemented with other strategies to support ongoing trial interest to randomisation and beyond. Participants refused trial participation throughout the screening phase indicating that the PICF was only one factor among several affecting an individual's decision to participate in this clinical trial.

•

A short and concise clinical trial document is recommended.

•

Avoiding lengthy and complex clinical trial documents may contribute to increasing older adult trial participation rates.

•

Strategies are sought to increase participation of older adults in research to garner more age-specific public health data.

Factors influencing the willingness to participate in medical research: a nationwide survey in Taiwan

Background

Participation rate is one of the main challenges medical researchers face. We examined how demographic background and trust in medical research affect the willingness of people to participate in medical research in Taiwan.

Methods

Data from the 2011 Taiwan Genomic Survey (a nationwide representative face-to-face survey) were analyzed. The survey included a vignette of a researcher conducting a clinical trial of an investigative medicinal product, and questions for interviewees regarding their willingness to participate in research after they were informed of the scenario description. A total of 3,159 people, aged 18 to 70 years, were sampled, and 1,538 of them completed the survey. With missing data excluded, a total of 1,389 respondents were included in the final analysis.

Results

About 12 percent of the respondents answered that they would be willing to participate in medical research. Respondents who had college degrees or above and were married or lived with significant others were less likely to participate in medical research. By contrast, male respondents, and respondents whose household family members had biomedicine-related degrees or had one themselves were more likely to participate in medical research. After adjustment for demographic factors, respondents were more likely to participate in medical research if: (1) they expressed trust in doctors conducting medical research; (2) they agreed that doctors would never ask them to join medical research studies that might harm them; (3) they thought that participating in a medical research study would be safe; and (4) they agreed that researchers had no selfish reasons for doing the medical research.

Discussion

Some of our findings, such as the effects of education level and marital status on participation in medical research, are different from most findings of previous studies conducted in other countries. This study is useful for developing strategies to improve participant recruitment. Relevant discussions on research ethics and policies, such as the importance of public trust in medical researchers, could also be based on this study.

European Prevention of Alzheimer's Dementia Registry: Recruitment and prescreening approach for a longitudinal cohort and prevention trials

INTRODUCTION

It is a challenge to find participants for Alzheimer's disease (AD) prevention trials within a short period of time. The European Prevention of Alzheimer's Dementia Registry (EPAD) aims to facilitate recruitment by preselecting subjects from ongoing cohort studies. This article introduces this novel approach.

METHODS

A virtual registry, with access to risk factors and biomarkers for AD through minimal data sets of ongoing cohort studies, was set up.

RESULTS

To date, ten cohorts have been included in the EPAD. Around 2500 participants have been selected, using variables associated with the risk for AD. Of these, 15% were already recruited in the EPAD longitudinal cohort study, which serves as a trial readiness cohort.

DISCUSSION

This study demonstrates that a virtual registry can be used for the preselection of participants for AD studies.

Women's experiences of participating in a prospective, longitudinal postpartum depression study: insights for perinatal mental health researchers

Barriers to recruitment for research on mental illness include participant distrust of researchers and social stigma. Though these issues may be acutely important in perinatal mental health research, they remain unexplored in this context. In order to inform strategies to more fully engage women in perinatal mental health research, we explored the motivations and experiences of women with a history of major depressive disorder who participated in a prospective longitudinal research study on postpartum depression (PPD). Sixteen women with a history of depression who had either completed or recently made a decision about participation in a longitudinal research study about PPD were interviewed by telephone. Qualitative, semi-structured interviews explored participants' decision-making about, and experiences of, participation. Interviews were audio-recorded, transcribed, and qualitatively analyzed using elements of grounded theory methodology. Follow-up interviews were conducted with four participants to refine and clarify preliminary results. Foundational elements necessary for women to consider participating in PPD research included personal acceptance of illness and trust in the research team/institution. Other main motivators included perceived personal relevance, anticipated benefits (including access to support/resources, learning opportunities, and improved self-worth), altruism, and accessible study procedures. Our data suggest that participating in perinatal mental health research may help women make meaning of their mental illness experience and is perceived as providing support. The findings-particularly around the importance of participant-researcher rapport and accessibility of study design-may inform strategies that improve participation rates, decrease attrition, and maximize participant benefits in perinatal mental health research.

A protocol for a systematic review of non-randomised evaluations of strategies to improve participant recruitment to randomised controlled trials

BACKGROUND

Randomised controlled trials guard against selection bias and therefore offer the fairest way of evaluating healthcare interventions such as medicinal products, devices and services. Recruitment to trials can be extremely difficult, and poor recruitment can lead to extensions to both time and budget and may result in an underpowered study which does not satisfactorily answer the original research question. In the worst cases, a trial may be abandoned, causing huge waste. The evidence to support the choice of recruitment interventions is currently weak. Non-randomised evaluations of recruitment interventions are currently rejected on grounds of poor methodological quality, but systematic evaluation and assessment of this substantial body of work (using Grading of Recommendations Assessment, Development and Evaluation (GRADE) where possible) may provide useful information to support and inform the recruitment decisions of trialists and the research priorities of methodology researchers.

METHODS

The following databases will be searched for relevant studies: Cochrane Methodology Register, MEDLINE, EMBASE, CINAHL and PsycINFO. Any non-randomised study that includes a comparison of two or more interventions to improve recruitment to randomised controlled trials will be included. We will not apply any restrictions on publication date, language or journal. The primary outcome will be the number of individuals or centres recruited into a randomised controlled trial. The secondary outcome will be cost per recruit. Two reviewers will independently screen abstracts for eligible studies, and then, full texts of potentially relevant records will be reviewed. Disagreements will be resolved through discussion. The methodological quality of studies will be assessed using the Cochrane risk of bias tool for non-randomised studies, and the GRADE system will be used if studies are pooled.

DISCUSSION

This review aims to summarise the evidence on methods used to improve recruitment to randomised controlled trials. Carrying out a systematic review including only data from non-randomised studies is a novel approach, and one which some may argue is futile. However, we believe that the systematic evaluation of what is likely to be a substantial amount of research activity is necessary, worthwhile, and will yield valuable results for the clinical trials community regardless of whether the outcomes find in favour of one or more interventions. Should the results of this review suggest that non-randomised evaluations do have something to offer trialists planning their recruitment strategies, the review may be combined in the future with the Cochrane review of randomised evaluations to produce a full review of recruitment strategies encompassing both randomised and non-randomised evaluation methods.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037718.

Analysis of four recruitment methods for obtaining normative data through a Web-based questionnaire: a pilot study

BACKGROUND

Quality normative data requires a diverse sample of participants and plays an important role in the appropriate use of health outcomes. Using social media and other online resources for survey recruitment is a tempting prospect, but the effectiveness of these methods in collecting a diverse sample is unknown. The purpose of this study is to pilot test four methods of recruitment to determine their ability to produce a sample representative of the general US population.

METHODS

This project is part of a larger study to gather normative data for the Michigan Hand Outcomes Questionnaire (MHQ). We used flyers, e-mail, Facebook, and an institution-specific clinical research recruitment Web site to direct participants to complete an online version of the MHQ. Participants also provided comorbidity and demographic information.

RESULTS

The institution-specific recruitment Web site yielded the greatest number of respondents in an age distribution that mirrored the US population. Facebook was effective for recruiting young adults, and e-mail was successful for recruiting the older adults. None of the methods was successful in reaching an ethnically diverse sample.

CONCLUSIONS

Obtaining normative data that is truly representative of the US population is a difficult task. The use of any one recruitment method is unlikely to result in a representative sample, but a greater understanding of these methods will empower researchers to use them to target specific populations. This pilot analysis provides support for the use of Facebook and clinical research sites in addition to traditional methods of e-mail and paper flyers.

Processing fluency effects: can the content and presentation of participant information sheets influence recruitment and participation for an antenatal intervention?

OBJECTIVE

To assess the extent to which the title and font of participant information sheets (PISs) can influence pregnant women's and trainee midwives' perceptions of an antenatal intervention.

METHODS

Pregnant women (n=35) and trainee midwives (n=36) were randomly presented with one of four PISs where the title and font of the PIS had been manipulated to create four experimental conditions (i.e., Double Fluent; Double Awkward; Fluent Title-Awkward Font; Awkward Title-Fluent Font). After reading the PIS, participants rated their perceptions of the intervention (i.e., Attractiveness, Complexity, Expected Risk, Required Effort) using five-point Likert scales.

RESULTS

A 4×2 factorial multivariate analysis of variance revealed that pregnant women rated the Double Awkward condition as significantly more complex than the Double Fluent (p=.024) and Awkward Title-Fluent Font (p=.021) conditions.

CONCLUSION

Font influenced pregnant women's ratings of intervention complexity.

PRACTICE IMPLICATIONS

Results have implications for ethical recruitment, and in turn, the optimisation of corresponding interventions.

Recruitment and Retention for Community-Based eHealth Interventions with Populations of Low Socioeconomic Position: Strategies and Challenges

Given persistent communication inequalities, it is important to develop interventions to improve Internet and health literacy among underserved populations. These goals drove the Click to Connect (C2C) project, a community-based eHealth intervention that provided novice computer users of low socioeconomic position (SEP) with broadband Internet access, training classes, a Web portal, and technical support. In this paper, we describe the strategies used to recruit and retain this population, the budgetary implications of such strategies, and the challenges and successes we encountered. Results suggest that personal contact between study staff and participants and provision of in-depth technical support were central to successful recruitment and retention. Such investments are essential to realize the promise of eHealth with underserved populations.